I personally don't care what others wear as it has no direct impact on my cruise experience. If Celebrity were going to suddenly start enforcing any rule I would much prefer it be the one that doesn't allow saving seats by the pool. Was just on a cruise and its very frustrating to get to the pool at 8am, intending to actually use the pool right then, and have literally every seat already "saved" and just sitting there empty, sometimes for hours. If Celebrity can't seem to manage something this blatant, that clearly impacts the cruising experience of other passengers, good luck getting them to hold anyone's feet to the fire over what they wear to dinner.